Heart wall motion: improved method of spatial modulation of magnetization for MR imaging.

Axel, Leon; Dougherty, Lawrence

doi:10.1148/radiology.172.2.2748813

Cited by 560 publications

(293 citation statements)

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“…An electrocardiograph triggered the segmented acquisition of k-space, using the spatial modulation of magnetization (SPAMM) tagging sequence as initially described by Axel et al (8) to create a tag grid on the images with a tag separation of 7 mm using a fast field echo (FFE) multishot sequence. The TR/TE ϭ 3.9 msec/1.69 msec with a voxel size ϭ 1.99/2.04/8.00 mm 3 , flip angle ϭ 5°, tag grid angle ϭ 45°with 12 msec and 10 -14 phases per cardiac cycle.…”

Section: Mr Taggingmentioning

confidence: 99%

“…In addition, quantifying degrees of function during stress testing or degrees of contraction asynchrony for predicting the response to cardiac resynchronization therapy can be performed (6,7). Currently, for cardiovascular magnetic resonance (CMR), MR tagging is widely used to measure myocardial strain (8,9). However, this method has some disadvantages, such as limited temporal resolution and the need for sophisticated and time-consuming methods for image processing.…”

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confidence: 99%

“…Recently, strain-encoded (SENC) imaging was introduced as a new method for measuring myocardial strain (8,10,11). In contrast to conventional tagging, SENC uses tag surfaces parallel-not orthogonal as in MR tagging-to the image plane combined with out-ofplane phase-encoding gradients along the slice-selected direction (11).…”

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confidence: 99%

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Strain‐encoded (SENC) magnetic resonance imaging to evaluate regional heterogeneity of myocardial strain in healthy volunteers: Comparison with conventional tagging

Neizel

Loßnitzer

Korosoglou

et al. 2008

Magnetic Resonance Imaging

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Purpose:To evaluate the ability of strain-encoded (SENC) magnetic resonance imaging (MRI) for regional systolic and diastolic strain analysis of the myocardium in healthy volunteers. Materials and Methods:Circumferential and longitudinal peak systolic strain values of 75 healthy volunteers (35 women and 40 men, mean age 44 Ϯ 12 years) were measured using SENC at 1.5T. MR tagging was used as the reference standard for measuring regional function. Diastolic function was assessed in the 10 youngest (24 Ϯ 8 years) and 10 oldest (62 Ϯ 5 years) subjects. Results:Peak strain values assessed with SENC were comparable to those obtained by MR tagging, showing narrow limits of agreement (limits of agreement -5.6% to 8.1%). Regional heterogeneity was observed between different segments of the left ventricle (LV) by both techniques (P Ͻ 0.001). Longitudinal strain obtained by SENC was also heterogenous (P Ͻ 0.001). Interestingly, no age-or genderspecific differences in peak systolic strain were observed, whereas the peak rate of relaxation of circumferential strain rate was decreased in the older group.Conclusion SENC is a reliable tool for accurate and objective quantification of regional myocardial systolic as well as diastolic function. In agreement with tagged MRI, SENC detected slightly heterogeneous myocardial strain within LV segments.

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Section: Mr Taggingmentioning

confidence: 99%

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confidence: 99%

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Strain‐encoded (SENC) magnetic resonance imaging to evaluate regional heterogeneity of myocardial strain in healthy volunteers: Comparison with conventional tagging

Neizel

Loßnitzer

Korosoglou

et al. 2008

Magnetic Resonance Imaging

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“…[2] were optimized in such a way that the simulated tag lines moved toward the dark stripes in the tagged images. The optimal control points were computed by minimizing the following weighted sum of the external and internal energy of the cylindrical B-spline model,…”

Section: Model Fittingmentioning

confidence: 99%

Combined tag tracking and strain reconstruction from tagged cardiac MR images without user‐defined myocardial contours

Deng¹,

Denney²

2004

Magnetic Resonance Imaging

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Purpose: To develop an unsupervised method for measuring quantitative three-dimensional regional strain in the left ventricular wall from tagged cardiac MR images. Materials and Methods:A total of 10 normal human volunteers and eight patients with myocardial infarction were imaged using a parallel tagged imaging protocol. Each study was analyzed using the combined tag tracking and strain reconstruction (COTTER) algorithm. In contrast to existing techniques, which first track tag lines independently in each slice, then reconstruct myocardial deformation, the COTTER algorithm fits a three-dimensional cardiac deformation model directly to the image data. This approach ensures that tag line positions identified in the image data are consistent from slice to slice. A total of 10 imaging studies (six normals, four patients) were used to optimize parameters of the COTTER algorithm.Results: In the remaining eight imaging studies, the rootmean-square difference between tags tracked by COTTER and user-supervised analysis was 0.66 pixels at end-systole. The correlation coefficient between circumferential shortening strains at end-systole computed by COTTER and user-supervised analysis was 0.84 (P Ͻ 0.005) at the midwall. Conclusion:The COTTER algorithm can compute accurate measurements of three-dimensional regional strain without user supervision.

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“…A 1-1 spatial modulation of magnetization (SPAMM) (6) sequence is applied prior to tissue compression. The sequence consists of two 90°, radiofrequency (RF) pulses separated by a magnetic-field gradient.…”

Section: Theorymentioning

confidence: 99%

Detecting stiff masses using strain‐encoded (SENC) imaging

Osman

2003

Magnetic Resonance in Med

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A method is proposed for detecting stiff masses using strainencoded (SENC) magnetic resonance imaging (MRI). An object of interest is compressed to produce local strain distribution that depends on local elasticity, where intensities correlate with the local through-imaging-plane strain component. Because the strain is lower inside a stiff mass than in the surrounding soft tissue, an intensity contrast in the resulting images would enable direct detection of the mass without postprocessing. The technique was validated by a phantom experiment in which a gel phantom with a stiff region was used. The advantages of the proposed method include short imaging time and uncomplicated postprocessing. However, in its current form the technique does not measure elasticity.Magn Reson Med 49: 605-608, 2003.

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Heart wall motion: improved method of spatial modulation of magnetization for MR imaging.

Cited by 560 publications

References 0 publications

Strain‐encoded (SENC) magnetic resonance imaging to evaluate regional heterogeneity of myocardial strain in healthy volunteers: Comparison with conventional tagging

Strain‐encoded (SENC) magnetic resonance imaging to evaluate regional heterogeneity of myocardial strain in healthy volunteers: Comparison with conventional tagging

Combined tag tracking and strain reconstruction from tagged cardiac MR images without user‐defined myocardial contours

Detecting stiff masses using strain‐encoded (SENC) imaging

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